Estimating user's engagement from eye-gaze behaviors in human-agent conversations

In face-to-face conversations, speakers are continuously checking whether the listener is engaged in the conversation and change the conversational strategy if the listener is not fully engaged in the conversation. With the goal of building a conversational agent that can adaptively control conversations with the user, this study analyzes the user's gaze behaviors and proposes a method for estimating whether the user is engaged in the conversation based on gaze transition 3-gram patterns. First, we conduct a Wizard-of-Oz experiment to collect the user's gaze behaviors. Based on the analysis of the gaze data, we propose an engagement estimation method that detects the user's disengagement gaze patterns. The algorithm is implemented as a real-time engagement-judgment mechanism and is incorporated into a multimodal dialogue manager in a conversational agent. The agent estimates the user's conversational engagement and generates probing questions when the user is distracted from the conversation. Finally, we conduct an evaluation experiment using the proposed engagement-sensitive agent and demonstrate that the engagement estimation function improves the user's impression of the agent and the interaction with the agent. In addition, probing performed with proper timing was also found to have a positive effect on user's verbal/nonverbal behaviors in communication with the conversational agent.